Original RIP method:
http://boscoh.com/rip/
Reference: "Probing the Flexibility of Large Conformational Changes in Protein Structures through Local Perturbations" by Bosco K. Ho and David A. Agard. PLoS Comput Biol 5(4): e1000343.
L-RIP & RIPlig methods:
Reference: "Perturbation approaches for exploring protein binding site flexibility to predict transient binding pockets" by Daria B. Kokh, Paul Czodrowski, Friedrich Rippmann and Rebecca C. Wade